JP2009522441A - Electrolyte and process for depositing a matte metal layer - Google Patents

Abstract

An electrolytic composition for the deposition of a matt metal layer onto a substrate and deposition process where the composition comprises a source of metal from the group consisting of Cr, Mn, Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, In, Sn, Sb, Re, Pt, Au, Bi, and combinations thereof; a substituted or unsubstituted polyalkylene oxide or its derivative as an emulsion and/or dispersion former; and a compound comprising fluorated or perfluorated hydrophobic chains or which is a polyalkylene oxide substituted quaternary ammonium compound as wetting agent; wherein the electrolytic composition forms a microemulsion and/or dispersion.

Description

  The present invention relates to an electrolyte and process for depositing a matte metal layer from an electrolyte comprised of an emulsion and / or dispersion former or wetting agent on a substrate.

  In the production of a metal layer on a substrate, the aim is generally to obtain a rather smooth and highly glossy coating. However, in special applications it is often desirable to obtain a matte metal coating with no gloss. The reason is the optical appearance and also the technical nature of the coating, i.e. the lack of brightness of such a coating. The field of application of matte deposited metal layers on substrates is particularly important in the absence of shine of these coatings, for example in the jewelry industry, furniture industry, automotive industry, and optics and precision industry. A nickel or nickel alloy layer with a matte deposit as well as a cobalt layer is known in the prior art. Although such potential allergenic metal deposits are not fatal in many fields, it is desirable to avoid these metals in the jewelry industry or also in the field of kitchen utensils and kitchenware. In the field of optics or precision industry, the deposition of matte metal layers of many different metals is desired due to the different properties of each metal. In addition, it is desirable to adjust the degree of matting of the deposited metal layer over a wide range.

  It is an object of the present invention to provide an electrolyte for a process for depositing a matte metal layer on a substrate and to deposit various metals on many different substrates to different matte degrees by this method.

  This object is achieved by an electrolyte consisting of an emulsion and / or dispersion former or wetting agent, the electrolyte being Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo. , Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, W, Re, Pt, Au, Tl, Pb, Bi, or a metal for depositing a group of metals consisting of alloys of these metals. Contain, emulsion and / or dispersion formation is a substituted or unsubstituted polyalkylene oxide or derivative thereof, does the wetting agent contain fluorinated or perfluorinated hydrophobic chains? Or a polyalkylene oxide substituted quaternary ammonium compound, and the electrolyte, emulsion and / or dispersion former or wetting agent is micromilk It is characterized by forming a liquid and / or dispersions.

  With respect to the process, the object is solved by the step of electrically depositing matte metal on the substrate, the substrate being connected to a power source in a galvanic bath consisting of an electrolyte and a counter electrode according to the present invention, and depositing a metal layer on the substrate A suitable voltage is applied between the substrate and the counter electrode.

  It has been discovered that the formation of a microemulsion in an electrolyte is suitable for the matte deposition of many different metals from the corresponding electrolyte. Furthermore, for the formation of microemulsions in many different metal electrolytes for deposition, polyalkylene glycols or their derivatives, wetting agents with fluorinated or perfluorinated hydrophobic chains and It has been found that quaternary ammonium compounds substituted by polyalkylene oxide chains are suitable. These compounds can be used for the preparation of emulsions in a wide range of many different metal electrolytes and can be used independently.

  If a polyalkylene glycol is used as the emulsion and / or dispersion former, a special polymer consisting of different percentages of hydrophilic and hydrophobic structures, preferably polyethylene and polypropylene glycols, is preferably used as a homogeneous polymer. It was found to be suitable for addition. In this case, it is the percentage of hydrophilic and hydrophobic structures that determines the degree of matting of the deposited metal layer depending on the average molecular weight, where the average molecular weight is> 200 g / mol, a high percentage of hydrophobic structures Is preferably 200 to 2000 g / mol, and preferably> 4000 g / mol for polymers with a higher percentage of hydrophilic structure.

When a fluoride or perfluoride wetting agent is used, a general wetting agent chemical formula is R ^f CH ₂ CH ₂ O (CH ₂ CH ₂ O) _X H (Formula 1)
R ^f = F (CF ₂ CF ₂ ) _n , where X = 6 to 15 and n = 2 to 10 are particularly suitable. The average molecular weight of the fluoride or perfluoride wetting agent is between about 550 and about 1000 g / mol, and preferably between about 700 and about 1000 g / mol according to the present invention. In this case, the average molecular weight also has an influence on the degree of matting.

ここで、少なくとも一つのＲ^１、Ｒ^２、Ｒ^３あるいはＲ^４基はポリアルキレン酸化物の置換基でそして残りの基は独立して同じかあるいは異なる直鎖か側鎖の飽和あるいは不飽和のＣ_１からＣ_１８のアルキル鎖でＸ⁻はハロゲン陰イオン、硫酸陰イオンあるいはＣ_１からＣ_６の炭酸陰イオンである。特に一般式２の第４級のアンモニウム化合物が適していることがわかり、Ｒ^１およびＲ^２はＣ_８からＣ_１２で、望ましくはＣ_１０アルキル側鎖、Ｒ^３はＣ_１からＣ_３で、望ましくはＣ_１アルキル側鎖、Ｒ^４は一般式［ＣＨ_２-ＣＨ_２-Ｏ］_ｎＨに一致し、ｎ＝１から５、そしてＸ⁻はＣ_２からＣ_４の炭酸陰イオンである。 Another type of wetting agent suitable for depositing a metal layer from an electrolyte according to the present invention is desirably a polyalkylene oxide substituted quaternary ammonium compound according to the following general formula:

Here, at least one R ¹ , R ² , R ³ or R ⁴ group is a substituent of the polyalkylene oxide and the remaining groups are independently the same or different linear or side chain saturated or unsaturated. In the C ₁ to C ₁₈ alkyl chain, X ⁻ is a halogen anion, a sulfate anion, or a C ₁ to C ₆ carbonate anion. It has been found that quaternary ammonium compounds of general formula 2 are particularly suitable, wherein R ¹ and R ² are C ₈ to C ₁₂ , preferably C ₁₀ alkyl side chains, R ³ is C ₁ to C ₃ , Desirably the C ₁ alkyl side chain, R ⁴ corresponds to the general formula [CH ₂ —CH ₂ —O] _n H, n = 1 to 5 and X ⁻ is a C ₂ to C ₄ carbonate anion.

  According to the present invention, the average molecular weight of the quaternary ammonium compound added to the electrolyte is between about 200 and about 1000 g / mol, preferably between about 400 and about 500 g / mol, more preferably about Between 450 and about 460 g / mol.

  Furthermore, the addition of polytetrafluoroethylene particles to the electrolyte according to the invention has an influence on the properties of the deposited matte metal layer. Thus, in the deposition of a matte metal layer from an electrolyte according to the present invention with the addition of polytetrafluoroethylene particles, a matte surface deposited from the electrolyte according to the present invention without the addition of polytetrafluoroethylene particles; By comparison, it is clear that the surface is quite soft with respect to the feel and shows a clearly low sensitivity to finger prints (free to touch).

  It has been discovered that the average particle diameter of the added polytetrafluoroethylene particles ranges from about 10 to about 1000 nm, desirably from about 100 to about 300 nm.

  In accordance with the present invention, polytetrafluoroethylene particles are added at a concentration between about 0.1 and 1000 mg / L, desirably between about 0.5 and 5 mg / L.

  The following examples illustrate the process according to the present invention as well as the embodiments of the electrolyte according to the present invention, but the present invention is not limited to these example embodiments.

Example 1
Cu electrolyte with the following composition:
55 g / L Cu ²⁺
66 g / L H ₂ SO ₄
100 mg / L Cl ⁻
200 mg / L bis- (3-sulfopropyl) -disulphide, disodium salt was mixed with 2 g / L polypropylene glycol having a molecular mass of 900 g / mol. Plating was done for 10 minutes on a square sheet with 5 A / dm ² and 35 ° C., moving the cathode at 2 m / min. No air movement is required. Surprisingly, a uniform pearl luster was obtained at high and low current density regions. There was no adhesion problem during the current interruption due to the small amount of organic brightener, and then the adhesion layer could be deposited from acidic bronze electrolyte or from trivalent chromium electrolyte. The degree of matte pearl luster effect can be controlled by the polymer concentration. All pearlescent luster is removed by a single filtration of Celite.

(Example 2)
When using the parameters described in Example 1, a stable and uniform pearlescent effect was added at 26 ° C. in place of the polypropylene glycol described in Example 1 with 300 mg / L of polyalkylene glycol having the following block polymer structure: To get:
HO— (CH ₂ —CH ₂ —O) _x — (CH ₂ —CH (CH ₃ ) —O) _Y — (CH ₂ —CH ₂ —O) _z —H
The average molecular weight is 1700 g / mol of the fraction (x + z) of polyethylene oxide which is 20% of the molecular mass.

(Example 3)
In a bronze electrolyte with the following composition:
12g / L Cu (II)
2g / L Sn (II)
10 g / L methanesulfonic acid 2 g / L hydroquinone current density 2 A / dm ² , 25 ° C. and block migration 1 m / min, molecular weight 5000 g / mol, 20% fraction block polymer structure shown in Example 2 A uniform pearlescent effect was also obtained with 5 mg / L polyalkylene glycol having

(Example 4)
In a Watt electrolyte with the following composition:
440 g / L Nickel sulfate 30 g / L Boric acid 40 g / L Nickel chloride 5 g / L Saccharin sodium salt 700 g / mol average molecular weight with a main composition characterized by X = 5 and Y = 10 Addition of a certain CF-substituted polyethylene glycol 10 g / L gives a uniform matting effect at a temperature of 52 ° C., a pH value of 4.2, a current density of 5 A / dm ² , and a cathode movement of 2 m / min after 10 minutes. was gotten.
F- (CF ₂ -CF ₂ ) _X- (CH ₂ -CH ₂ -O) _Y -H

(Example 5)
In Example 4, when the CF ₂ -substituted polyethylene glycol was replaced with an ammonium compound substituted with polyethylene glycol, a uniform matte effect was obtained with a different structure than in Example 4. For example, a nickel-plated brass sheet having a pearly luster effect was obtained by adding 8 mg / L didemethylmethyl- (oxethyl) ammonium propionate to the same watt electrolyte as in Example 4.

(Example 6)
The polyethylene glycol substituted ammonium salt emulsion prepared in Example 5 was added with 1 mL / L of PTFE suspension (Zonyl TE3367-N, Dupont), which resulted in different structure and properties of the layers. .

  The surface thus produced showed the effect of repelling strong hydrophobic dust.

Claims (11)

An electrolyte for depositing a matte metal layer on a substrate from an electrolyte consisting of an emulsion and / or a dispersion former or wetting agent,
The electrolytes are Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, W, Re Pt, Au, Tl, Pb, Bi or containing metals for depositing metals of the group consisting of these metals, emulsions and / or dispersion formations are substituted or substituted Non-polyalkylene oxide or derivative thereof, the wetting agent contains a fluorinated or perfluorinated hydrophobic chain or is a polyalkylene oxide-substituted quaternary ammonium compound, and an electrolyte, emulsion And / or the dispersion former or wetting agent is characterized by forming a microemulsion and / or dispersion.   The electrolyte of claim 1 wherein the emulsion and / or dispersion former is a substituted or unsubstituted polyethylene oxide, polypropylene oxide, polypropylene-polypropylene oxide block copolymer or mixtures thereof.   The emulsion and / or dispersion former has an average molecular weight> 200 g / mol, preferably 200 to 2000 g / mol for a polymer with a high percentage of hydrophobic structure, and a polymer with a higher percentage of hydrophilic structure Then, preferably the electrolyte solution of Claim 2 which has> 4000g / mol. The electrolyte of claim 1, wherein the fluorinated or perfluorinated wetting agent desirably has the general formula:
^{_{R f CH 2 CH 2 O (}} CH 2 CH 2 O) X H
R ^f = F (CF ₂ CF ₂ ) _n , where X = 6 to 15 and n = 2 to 10.   The electrolyte of claim 4, wherein the wetting agent has an average molecular weight between about 550 and about 1000 g / mol, and preferably between about 700 and about 1000 g / mol. The polyalkylene oxide substituted quaternary ammonium compound used as a wetting agent has the general formula:

At least one R ¹ , R ² , R ³ or R ⁴ group is a polyalkylene oxide substituent and the remaining groups are independently from the same or different linear or side chain saturated or unsaturated C _1. alkyl chains a and X a C ₁₈ ^- is a halogen anion, the electrolytic solution of claim 1 which is carbonate anions to C ₆ sulfate anions or C _1. R ¹ and R ² are C ₈ to C ₁₂ , preferably C ₁₀ alkyl side chains, R ³ is C ₁ to C ₃ , preferably C ₁ alkyl side chains, R ⁴ is a compound of the general formula [CH ₂ -CH _{2 -O]} n H, matches from n = 1 to 5, and X ^- electrolyte according to claim 6 is a carbonate anion _{to C 4 C 2.}   8. The electrolysis of claim 7, wherein the average molecular weight of the wetting agent is between about 200 and about 1000 g / mol, desirably between about 400 and about 500 g / mol, and more desirably between about 450 and about 460 g / mol. liquid.   The electrolyte of any one of the preceding claims, wherein the electrolyte additionally comprises polytetrafluoroethylene particles having an average particle diameter of about 10 to about 1000 nm, desirably about 100 to about 300 nm.   The electrolyte of claim 9 wherein the electrolyte comprises polytetrafluoroethylene particles at a concentration between about 0.1 and 1000 mg / L, desirably about 0.5 to 5 mg / L.   A substrate is connected to a power source and a counter electrode in a galvanic bath containing an electrolyte according to one of claims 1 to 10 and a voltage suitable for depositing a metal layer on the substrate is applied between the substrate and the counter electrode. The process of electrolytically depositing a matte metal layer on a substrate.